1. Field of the Invention
The present invention relates to a digital signal processor which performs several kinds of signal processings on digital signals.
2. Prior Art
In the fields of the communication system, sound processing system and the like, a digital signal processor (i.e., DSP) is used when performing several kinds off signal processings on the digital signals inputted thereto. Every time a new sample of digital signal to be processed is entered, the DSP performs a plurality of arithmetic and logical operations on the basis of parameters. The parameters are determined responsive to a predetermined number of the samples which are previously inputted to the DSP, or they are determined responsive to results of operations which were previously carried out. For this reason, an extremely high performance is required for the DSP when performing the above-mentioned signal processings. Conventionally, several kinds of hardware configurations are studied in order to carry out a large scale and complicated signal processing.
Accompanied with a recent progress of the semiconductor manufacturing techniques or an improvement in the design of the hardware configuration for the semiconductor devices, some DSP can carry out a high-speed signal processing. However, the DSP is designed as the processor of which fundamental configuration is based on the von Neumann architecture of the general-use computer system. In such processor, the instructions are sequentially carried out step by step in a predetermined period. Thus, the time required for performing the signal processing in the DSP should be determined responsive to a number of operation steps included in the signal processing to be carried out. This causes a drawback in that a processing speed must be limited when performing a large-scale and complicated signal processing.